George,
I've communicated with a gentleman by the name of Ken Legendre, who frequently posts on the Civil War Flags and Louisiana Message Boards. Ken has been researching Confederate Color Guards and Color Bearers for a few years now, presumably to ultimately publish a book. He confirms from his materials that this man was a color bearer, which agrees with your information.
Still, that A.C.S. makes me wonder if he might have been both a flag bearer and a commissary sergeant, at different points in time.
Jim